class_docstr: Stores the state of a model. For example, the running statistics of all
  [`equinox.nn.BatchNorm`][] layers in the model.
  
  This is essentially a dictionary mapping from [`equinox.nn.StateIndex`][]s to
  PyTrees of arrays.
  
  This class should be initialised via [`equinox.nn.make_with_state`][].
docstr: Given an [`equinox.nn.StateIndex`][], returns the value of its state.
  
  **Arguments:**
  
  - `item`: an [`equinox.nn.StateIndex`][].
  
  **Returns:**
  
  The current state associated with that index.
docstr_tok: ["Given","an","[","`","equinox.nn.StateIndex","`","]","[","]",",","returns","the","value","of","its","state",".","*","*","Arguments",":","*","*","-","`","item","`",":","an","[","`","equinox.nn.StateIndex","`","]","[","]",".","*","*","Returns",":","*","*","The","current","state","associated","with","that","index","."]
code: def get(self, item: StateIndex[_Value]) -> _Value:
      """Given an [`equinox.nn.StateIndex`][], returns the value of its state.
  
      **Arguments:**
  
      - `item`: an [`equinox.nn.StateIndex`][].
  
      **Returns:**
  
      The current state associated with that index.
      """
      if self._state is _sentinel:
          raise ValueError(_state_error)
      if type(item) is not StateIndex:
          raise ValueError(
              "Can only use `eqx.nn.StateIndex`s as state keys."
          )
      return self._state[item.marker]
  
imports: import types
  from collections.abc import Callable
  from typing import Any, Generic, TYPE_CHECKING, TypeVar, Union
  from typing_extensions import ParamSpec
  import jax
  import jax.numpy
  import jax.tree_util
  from jaxtyping import PyTree
  from .._module import field, Module
  from .._pretty_print import bracketed, named_objs, text, tree_pformat
  from .._tree import tree_at, tree_equal
label_desc: Use image node_id 2 for calling the State obj's underlying member method code with example usage: obj.get(item) and returns: self